Michael Sheen’s new BBC documentary, Buried with Michael Sheen, has brought renewed attention to a difficult and long-running issue – the legacy of historic industrial contamination in Wales.
For those working in South Wales, the subject has particular resonance. The region’s long industrial history means today’s development sites can sit on or alongside former chemical works, factories, quarries, railways, landfills and other industrial uses.
At Earth Science Partnership, we regularly work with the legacy of this historic land use and the programme provides a timely reminder of why understanding a site’s history and environmental setting is such an important part of responsible land development.
Contamination does not simply disappear with time
The two-part BBC investigation examines allegations surrounding the historic disposal of polychlorinated biphenyls (PCBs) at sites across Wales and the potential consequences for communities and the environment decades later (The Guardian).
PCBs are persistent chemicals whose use has been heavily restricted and banned. Natural Resources Wales continues to regulate PCB-containing equipment as hazardous waste and persistent organic pollutants. (NRW – PCB Regulation).
But the wider lesson extends beyond PCBs.
Depending on a site’s former use, investigations may need to consider hydrocarbons, metals, solvents, tars, landfill-related contaminants and other chemicals.
The age of a contamination source does not, by itself, determine whether it remains relevant. What matters is the relationship between the contaminant, ground conditions, potential pathways and the people or environmental receptors that could be affected.
Understanding South Wales’ industrial history
A site that appears vacant or benign today may once have contained industrial buildings, storage areas, railway infrastructure, workshops or waste disposal areas.
This makes understanding a site’s history just as important as understanding its geology.
Earth Science Partnership’s Phase 1 Desk Studies bring together historical information, environmental setting and site observations to identify potential constraints, including contamination risks. Where necessary, this can inform a proportionate programme of further investigation.
Identifying potential issues early can allow them to be investigated and managed before they become unexpected problems during design or construction.
Investigation is about understanding risk – not simply finding contamination
The presence of a contaminant does not automatically mean that land is unsafe or unsuitable for development. The significance of contamination depends on factors such as its concentration and distribution, the proposed use of the site, geology and hydrogeology, potential pathways and receptors.
Welsh planning policy recognises the need for specialist investigation and assessment to establish whether contamination presents an unacceptable risk and what remedial measures, if any, may be required.
Natural Resources Wales similarly describes land contamination as an issue that can arise from historic industrial, commercial or landfilling activities and highlights the potential implications for human health, ecosystems, property and water quality (Natural Resources Wales).
The key question is not simply:
“Is there contamination here?”
It is:
“Is there a plausible pollutant linkage, what risk does it present, and what needs to be done about it?”
The importance of getting the history right
One of the wider lessons from the story highlighted by Buried with Michael Sheen is the value of historical information.
Historical mapping, planning records, aerial photographs, previous investigations and knowledge of former site uses can all help establish what may have happened on a piece of land.
That information can then be used to develop a Conceptual Site Model — an evolving understanding of potential contamination sources, pathways and receptors.
The recently revised BS 10175:2026, the British Standard for investigation of potentially contaminated sites, places continued emphasis on developing and reviewing a Conceptual Site Model as an important part of the investigation process.
After decades of working across South Wales and beyond, Earth Science Partnership has encountered a wide range of ground conditions and historic land uses. That experience helps inform practical investigations that are proportionate to the risks and characteristics of individual sites.
A reminder for developers and landowners
It would be wrong to suggest that every former industrial site in South Wales presents a significant contamination risk. Equally, historic contamination should not be dismissed simply because industrial activity ended decades ago.
The sensible approach is to understand the history and environmental setting early, identify potential risks, investigate where necessary and establish an appropriate strategy for managing those risks.
That might mean no further action is required. In other cases, targeted investigation, monitoring, remediation or management measures may be appropriate.
From historic problems to responsible development
South Wales continues to regenerate former industrial areas and bring brownfield land back into productive use. Historic contamination is one consideration within a much wider picture that can also include ground stability, flooding, geology, groundwater and mining.
Buried with Michael Sheen has brought the issue of historic PCB contamination to a national audience. Its wider message is equally relevant to those developing land across South Wales: understanding the past can be essential to developing land responsibly for the future.
At Earth Science Partnership, we bring together geotechnical, geological and environmental expertise to help clients understand their sites, identify potential constraints and develop practical, evidence-based solutions – from early feasibility and site investigation through to assessment, remediation and development.
Get in touch today to understand how our knowledge, experience and expertise can help you understand your site’s history and future development considerations.
